How does artificial intelligence work?

There is no single way in which artificial intelligence works. One definition of AI is when a computer can solve a problem that normally requires a level of intelligence. Over the past 60 or so years, many different approaches to solving a wide variety of problems have been discovered by AI researchers. For example, chess can now be played by computers such as Deep Blue at a Grand Master level. It works by examining many thousands of chess board configurations, to see the future result of making particular moves. Another example is expert systems, which solve problems in areas such as medicine and engineering by duplicating the problem solving performed by real human experts. Other problems are more difficult. For example, making computers read and communicate in English is very challenging, and is far from solved.